AIO-CM4-156 Raspberry Pi OS Start Guide

Setting up your AIO-CM4-156


This manual provides users with a quick start guide of Chipsee Raspberry Pi Computer (Abbreviated as RPC) after you have reflashed the latest Raspberry official released OS. Through this manual, users can quickly set up their AIO-CM4-156 to run Raspberry Official latest released OS.









What you will need


This device only supports 12V Power Supply.

Installing the Operating System

You can reference Installing operating system images to know how to install the Operating System on your SD card.

Start up your AIO-CM4-156

  1. Insert the SD card to SD Slot of AIO-CM4-156.

  2. Power On.

Install CMhelper

  1. Add the following lines in your /boot/config.txt file:

  2. Add cmhelper PPA to your system manually by copying the lines below to your system’s software sources /etc/apt/sources.list.d/cmhelper.list:

    deb bionic main
    deb-src bionic main
  3. Update list of available packages:

    $ sudo apt update

    You will get error “the public key is not available: NO_PUBKEY 06D92B49B9078A87”, you should use follow commands to receive key from ubuntu key server:

    $ sudo apt-key adv --keyserver --recv-keys 06D92B49B9078A87

    If the above commands are not usable and you get a warning “apt-key is deprecated. Manage keyring files in trusted.gpg.d instead” run the following commands instead:

    $ sudo gpg --no-default-keyring --keyring gnupg-ring:/etc/apt/trusted.gpg.d/cmhelper.gpg --keyserver --recv 06D92B49B9078A87
    $ sudo chmod 644 /etc/apt/trusted.gpg.d/cmhelper.gpg

    or use the following commands if the above commands don’t work:

    $ sudo gpg --keyserver --recv 06D92B49B9078A87
    $ sudo gpg --export --armor 06D92B49B9078A87 | sudo apt-key add -


The key 06D92B49B9078A87 may be different from your error message, you should check your error, and use the right key.

  1. Install cmhelper:

    $ sudo apt update
    $ sudo apt install cmhelper
    $ sudo reboot


Be sure to reboot after installing cmhelper.

  1. Fix volume function.

    If the volume button doesn’t work, try to use the following ways to fix it.

    New one file name volen.dts:

    / {
        compatible = "brcm,bcm2835";
        fragment@0 {
            target = <&cam1_reg>;
            __overlay__ {
                status = "disabled";

    Then compile it to dtbo and copy it to /boot/overlays/:

    $ dtc -I dts -O dtb -o volen.dtbo volen.dts
    $ sudo cp volen.dtbo /boot/overlays/

    Add follow in /boot/config.txt:


    reboot to check again.

How to use CMHelper


The CMHelper can help customer use keys and onboard buzzer, led, you can use it to control volume, brightness, power, act led, buzzer.

  1. Buzzer can be enabled and disabled, if you enable buzzer function, you can open and close buzzer, otherwise, you can’t control the buzzer.

  2. The act led is disabled default, if you enable it, you can use it like ACT LED on Raspberry Pi.

  3. The product has two boot modes, the default is manual boot, you should press the power key to boot system. If you want to boot system directly after power, you can select auto boot.

  4. You can use CMHelper QT application or physical keys to control backlight.

  5. This QT Application is open sourced, you can recompile it with the following commands:

    $ sudo apt update
    $ sudo apt install qt5-default
    $ git clone
    $ cd cmhelper_tester
    $ qmake
    $ make
  6. There is also one C file for you to use:

    $ cd cmhelper_tester/c
    $ gcc -o cmhelper_test -lcmhelper cmhelper_test.c


This document is provided strictly for informational purposes. Its contents are subject to change without notice. Chipsee assumes no responsibility for any errors that may occur in this document. Furthermore, Chipsee reserves the right to alter the hardware, software, and/or specifications set forth herein at any time without prior notice and undertakes no obligation to update the information contained in this document.

While every effort has been made to ensure the accuracy of the information contained herein, this document is not guaranteed to be error-free. Further, it does not offer any warranties or conditions, whether expressed orally or implied in law, including implied warranties and conditions of merchantability or fitness for a particular purpose. We specifically disclaim any liability with respect to this document, and no contractual obligations are formed either directly or indirectly by this document.

Despite our best efforts to maintain the accuracy of the information in this document, we assume no responsibility for errors or omissions, nor for damages resulting from the use of the information herein. Please note that Chipsee products are not authorized for use as critical components in life support devices or systems.

Technical Support

If you encounter any difficulties or have questions related to this document, we encourage you to refer to our other documentation for potential solutions. If you cannot find the solution you’re looking for, feel free to contact us. Please email Chipsee Technical Support at, providing all relevant information. We value your queries and suggestions and are committed to providing you with the assistance you require.